Materials for high-capacity hydrogen storage

• Applicants: Dr. Claudio Pistidda; Professorin Dr. Astrid Pundt
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 425395402

The use of fossil fuels as an energy supply becomes increasingly problematic from the point of view of both environmental emissions and energy sustainability. As an alternative, hydrogen is widely regarded as a key element for a potential energy solution. However, differently from fossil fuels such as oil, gas and coal, hydrogen is a secondary energy source, which means that its production also requires energy. The possibility to produce hydrogen utilizing different and intermittent renewable resources such as solar energy, wind energy, etc., presents multiple advantages. On the one hand it will contribute to a remarkable reduction of pollutants released to the air, and on the other hand it will significantly enhance the security of energy supply. In addition, the implementation of hydrogen as “energy carrier” will result in an effective and synergic utilization of the renewable energy resources. In this respect, hydrogen storage technology is considered a key roadblock towards the use of H2 as an energy carrier. Among the methods available to store hydrogen, solid-state storage appears to be the most attractive alternative from both the safety and the volumetric energy density points of view. Recently, because of their appealing gravimetric and volumetric hydrogen storage properties, complex hydrides and Reactive Hydride Composite systems (RHCs) attracted considerable attention as potential hydrogen storage materials for mobile and stationary applications. However, despite the promising thermodynamic properties and hydrogen storage capacities, the issue of sluggish hydrogenation/de-hydrogenation kinetics is perhaps the primary challenge to be addressed before considering this class of material suitable for real applications. In this context, the project aims to investigate hydrogenation/de-hydrogenation processes in RHCs via a unique combination of transmission electron microscopy (TEM) and X-ray/neutron based techniques also under operative conditions (i.e. in situ). The (long-term) goal is to gain a comprehensive understanding of the factors that play a key role in nucleation, growth and diffusion processes in RHCs. This work will make the basis for the development of the first evidence-based crystallographic-chemical theory of nucleation and growth in the RHC systems and to unveil the mechanisms of diffusion and mass transport in the RHC systems. In turn, the knowledge generated within this project will help in identifying/designing new additives for the RHC systems that from one side will help to perform the hydrogenation/de-hydrogenation process under thermodynamically expected temperature and hydrogen pressure conditions and from the other side will prove the developed theory.

• DFG Programme: Research Grants